The 48-year-old Brentwood resident was gunned down during a traffic stop July 22.

Lunger stopped a vehicle whose driver was "observed driving erratically," police said. He got out of his car and approached the driver's side of the vehicle, but its occupant — suspect Mark Estrada of Oakland — opened fire without warning, police added. The 15-year veteran police officer succumbed to his injuries.

A’s players kicked things off by wearing special Hayward Police Department hats during batting practice. The hats were also sold during a silent auction with proceeds benefitting the Hayward Police Association.

The Oakland Police Department and Alameda County Sheriff’s Office presented the colors for the national anthem, which was performed on the trumpet by San Jose police officer Robert Payne. Lunger’s teammates from the Tri-Valley A’s also joined the A’s on the field during the national anthem.